Blalock, Ann.B, ed Blalock,Hubert M, ed <br/><br/>
Methodology in social research 

 - London  McGraw-hill, inc.  1971 
 - 493 p.; 20cm. 
 - McGraw-hill series in sociology .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Field work<br/>Research methodology<br/>Social research